In the case of known tools, the cutting tool, for example a cutting bit, is fastened in the receiving recess of the tool body in that an internal thread is provided in the tool-body bore. A fastening screw having a corresponding external thread engages in this internal thread, which fastening screw engages from the outside, first through the cutting-tool bore in the cutting tool, and then into the tool-body bore, and is then screwed tight. However, in the case of automated longitudinal turners, in which such tools, so-called longitudinal turning tools, are frequently used, there is often little space available for replacing the cutting tool, which is a wearing part and has to be changed frequently, while the tool body remains clamped into the machine tool. Since, in the case of the known tools, the screw by which the cutting tool is fastened to the tool body is accessible only from one side, however, in order to change the cutting tool it is therefore often necessary to remove the entire tool from the machine tool and to refit it after the cutting tool has been changed. This is very time-consuming, and is to be prevented according to the invention.
A tool wherein the fastening means for fastening the cutting tool to a tool body are accessible from two opposing sides, and wherein the problem described above has already basically been solved, is known from WO 2003/074217. In that case, a special fastening element is used to fasten the cutting tool to the tool body, which fastening element has, at its front end, special screw-shaped clamping wings, which act together with corresponding support wings within the cutting-tool bore, in the manner of a thread. In this case, screwing the fastening element into the cutting-tool bore causes the cutting tool to be fastened to the tool body, although the fastening element for tightening or undoing from both sides can be turned by means of differing keys.